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            <h2 class="title" style="clear: both"><a id="log_config"></a>Configuring logging</h2>
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      <p>
        The aspects of logging that may be configured are the size
        of the logging subsystem's region, the size of the log files
        on disk, the size of the log buffer in memory, and several
        operating system settings affecting the behavior of log files.
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      <p>
        The <a href="../api_reference/C/envset_lg_regionmax.html" class="olink">DB_ENV-&gt;set_lg_regionmax()</a> method specifies the size of the logging
        subsystem's region, in bytes. The logging subsystem's default size
        is approximately 60KB. This value may need to be increased if a
        large number of files are registered with the Berkeley DB log
        manager, for example, by opening a large number of Berkeley DB
        database files in a transactional application.
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        The <a href="../api_reference/C/envset_lg_max.html" class="olink">DB_ENV-&gt;set_lg_max()</a> method specifies the individual log file
        size for all the applications sharing the Berkeley DB
        environment. Setting the log file size is largely a matter of
        convenience and a reflection of the application's preferences
        in backup media and frequency. However, setting the log file
        size too low can potentially cause problems because it would
        be possible to run out of log sequence numbers, which requires
        a full archival and application restart to reset. See <a class="xref" href="log_limits.html" title="Log file limits">Log file limits</a> for more
        information.
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        The <a href="../api_reference/C/envset_lg_bsize.html" class="olink">DB_ENV-&gt;set_lg_bsize()</a> method specifies the size of the
        in-memory log buffer, in bytes. Log information is stored in
        memory until the buffer fills up or transaction commit forces
        the buffer to be written to disk. Larger buffer sizes can
        significantly increase throughput in the presence of
        long-running transactions, highly concurrent applications, or
        transactions producing large amounts of data. By default, the
        buffer is approximately 32KB.
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        The <a href="../api_reference/C/envset_lg_dir.html" class="olink">DB_ENV-&gt;set_lg_dir()</a> method specifies the directory in which
        log files will be placed. By default, log files are placed in
        the environment home directory.
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        The <a href="../api_reference/C/envset_lg_filemode.html" class="olink">DB_ENV-&gt;set_lg_filemode()</a> method specifies the absolute file
        mode for created log files. This method is only useful for the
        rare Berkeley DB application that does not control its umask
        value.
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        The <a href="../api_reference/C/envlog_set_config.html" class="olink">DB_ENV-&gt;log_set_config()</a> method configures several boolean
        parameters that control the use of file system controls such
        as O_DIRECT and O_DSYNC, automatic removal of log files,
        in-memory logging, and pre-zeroing of logfiles.
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